I think your wasting your time with Side draughts (aka webers, dellortoes and Su's etc) on bog stock motor, there is not enough gain to warrant this extra fuel with no improvments to the motor.

You are best spending your moeny on the motor improvements such things as Cam, head work, extractors, some bottom end work etc...these all lead to a more improved motor in terms of Flow, HP and RPM. THen a set of side draughts would be warrented to provide the fuel, better revabilty and greater performance. You would see a marked improvement from sidedraughts on a motor that is built for them. Look at the Aseries the motors with factory side daughts were on the more improved motor SSS / GX.

I am also pretty sure that a bog stock Aseries will not even run with twin carbies, the cam is not large enough.. maybe SU's tuned down alot but not Webers, could i be wrong?

The amount of carbies and what type of carbies also depend on the motors CC's of course.

Other factors come into play with turbo and superchargers.

But dont be put off, side draught carbies are a hell of alot of fun with the right motor!!!